title: RTOG GU Radiation oncology specialists reach consensus on pelvic lymph node volumes for high-risk prostate cancer.
abstract: OBJECTIVE
  Radiation therapy to the pelvic lymph nodes in high-risk prostate cancer is required on several Radiation Therapy Oncology Group (RTOG) clinical trials. Based on a prior lymph node contouring project, we have shown significant disagreement in the definition of pelvic lymph node volumes among genitourinary radiation oncology specialists involved in developing and executing current RTOG trials.
  
  
  METHODS
  A consensus meeting was held on October 3, 2007, to reach agreement on pelvic lymph node volumes. Data were presented to address the lymph node drainage of the prostate. Extensive discussion ensued to develop clinical target volume (CTV) pelvic lymph node consensus.
  
  
  RESULTS
  Consensus was obtained resulting in computed tomography image-based pelvic lymph node CTVs. Based on this consensus, the pelvic lymph node volumes to be irradiated include: distal common iliac, presacral lymph nodes (S(1)-S(3)), external iliac lymph nodes, internal iliac lymph nodes, and obturator lymph nodes. Lymph node CTVs include the vessels (artery and vein) and a 7-mm radial margin being careful to "carve out" bowel, bladder, bone, and muscle. Volumes begin at the L5/S1 interspace and end at the superior aspect of the pubic bone. Consensus on dose-volume histogram constraints for OARs was also attained.
  
  
  CONCLUSIONS
  Consensus on pelvic lymph node CTVs for radiation therapy to address high-risk prostate cancer was attained and is available as web-based computed tomography images as well as a descriptive format through the RTOG. This will allow for uniformity in evaluating the benefit and risk of such treatment.
authors.affiliation: Medical College of Wisconsin, Milwaukee, 53226, USA. clawton@mcw.edu
authors.forename: Colleen A F
authors.initials: CA
authors.lastname: Lawton
authors.forename: Jeff
authors.initials: J
authors.lastname: Michalski
authors.forename: Issam
authors.initials: I
authors.lastname: El-Naqa
authors.forename: Mark K
authors.initials: MK
authors.lastname: Buyyounouski
authors.forename: W Robert
authors.initials: WR
authors.lastname: Lee
authors.forename: Cynthia
authors.initials: C
authors.lastname: Menard
authors.forename: Elizabeth
authors.initials: E
authors.lastname: O'Meara
authors.forename: Seth A
authors.initials: SA
authors.lastname: Rosenthal
authors.forename: Mark
authors.initials: M
authors.lastname: Ritter
authors.forename: Michael
authors.initials: M
authors.lastname: Seider
mesh_terms: D006801:Humans; D008197:Lymph Node Excision / Q000592:standards; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D015182:Lymphatic Irradiation / Q000592:standards*; D008297:Male; D010388:Pelvis; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D018787:Radiation Oncology / Q000592:standards*; D011879:Radiotherapy Dosage; D012007:Rectum / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000592:standards; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014572:Urology / Q000592:standards*